Combustion engine



April 23, 1940. A. SCHUTTE 2,198,516

COMBUSTION ENGINE Filed Dec.. 28, 1957 FROM OIL. PUMP a7. jail/fizz e,

Patented Apr. 23, 1940 COMBUSTION nema 7 Alfred Schiitte, Augsburg, Germany, assignor to Maschinenfabrik Augaburg-Niirnberg A.

Augsburg, Germany, a corporation of Germany Application December 28, 1937, Serial No. 182,082 In Germany December 28, 1936 1 Claim.

My invention relates to internal combustion engines and more especially to that type of combustion engine which maybe selectively used either for operation as a gas or a Diesel motor.

5 Such interchangeable motors have already come into use in plants in which a gas supply is not always available. Where a Diesel motor is converted into a gas motor, the fuel valves and fuel pumps must be removed, and in their places spark-plugs and an ignition device must beinstalled. Further, a gas conduit together with the necessary mixing devices and connections to the regulator must be installed, and the compression space must be correspondingly enlarged. While u all these more or less minor changes can be made in a comparatively short time, there is the disadvantage that the output of the gas motor is not the same as that of the Diesel motor. If one were going to use a charge in the gas motor large enough to obtain the same output as in the Diesel motor, or if a charged Diesel motor were to be converted into a gas motor of the same output, considerable reconstruction would become necessary. While in a charged Diesel motor only a a motor driven enclosed blower, or an exhaust turbo-blower for air is provided, there must be provided in a charged gas motor several conduits, several control elements and a special blower for the gas, not to mention the fact that the blower a for the air is too large, when the motor operates as gas motor. All these changes are very extensive and would greatly increase the cost of an interchangeable motor.

To avoid this great drawback is the object of this invention, according to which in case the motor is used as a gas motor, after the scavenging of the cylinder with pure air, pure gas such as natural gas, is drawn in, followed by a charge of compressed air. When the motor is operated m as a Diesel motor, instead of the pure gas air under atmospheric pressure is drawn in. Such a combustion engine can be converted with a minimum of time and labor from a gas motor into a Diesel motor, and vice versa. Besides the 45 changes required in an uncharged interchangeable motor, to wit substitution of a fuel injection device for the ignition device and change of the compression, it is necessary only to sever the gas conduit from the gas supply and to connect it 50 with the outside air. The charged interchangeable motor embodying the invention is considerably simple in construction.

In the appended drawing I have diagrammatically shown, by way of illustration, an embodiment of the invention.

It is to be understood that throughout the following specification and claim whenever the expressions gas or pure gas" are used there is meant a permanent fuel gas, such as natural gas, illuminating gas or producer gas, as distinct from 5 vapors from a liquid hydrocarbon fuel or a mixture of such vapor with air.

In the drawing, the engine cylinder is indicated by the letter C, having a cylinder head 0'. This head is provided with three openings or passages 10 l6, l1 and it, one whereof, shown at It, has a reduced lower end provided with a downwardly facing valve seat lGa. This passage I6 also has an internal rib lib extending around its interior.

In the passage I6 is fitted a valve cage i6c closing the upper end of the passage. The rib 16b provides an inner annular channel 4' and anouter annular channel 6', the cage being seated in the reduced lower end and having said rib lib engaging its outer surface. The cage is provided with 20 air inlet openings 3 and gas inlet openings 5. At

I is shown the inlet valve. On the stem Id of the latter is mounted a slide-valve shown at 2 adapted to control the air inlet openings shown at 3 and the gas inlet openings shown at 5. At 4 is shown the air supply port and at 6 the gas supply port. The ports 4 and 6 open respectively into the passages 4' and i. To the air supply port 4 is connected the air supply conduit I, while to the gas supply port 6 is connected the gas supply conduit I. At 9 is shown a short conduit connecting the gas supply port 6 with the outside air. In the gas supply port 6 is gas-tightly mounted a rotary three way valve shown at i0, which can be so adjusted that selectively either the gas supply conduit 8 leading to the gas tank shown at l4 or the conduit 9 leading to the outside air, can be cut ofi.

With the rotary three way valve l0 occupying the position shown in the drawing. the combustion engine can be operated as a gas motor. In that case, compressed scavenging air is first introduced into cylinder C through the air supply conduit I, air supply port 4 and the inlet openings 3. Thereupon, the slide valve 2 is moved to cover up the air inlet openings 3 while uncovering the gas inlet openings 5, so that the descending piston (not shown) in cylinder C can draw in gas from the gas supply conduit 8 through the open rotary threeway valve ill, the gas supply port 6 and the inlet openings 5. By a subsequent upward displacement of the slide-valve 2 the gasinlet openings 5 are closed and the air inlet-openings 3 are opened again sothat compressed air can be charged into cylinder C through the airll supply conduit I, the air-supply port 4 and the inlet openings 3. The air supply conduit I is connected to a turbo-blower shown at I8 and operated by the waste-gas turbine shown at l2.

The passage l'l forms a fuel inlet passage for operation of the engine as a Diesel engine. In the passage II is fitted a valve cage I84 wherein is formed an exhaust pe l8b controlled by a poppet valve II, the stem Ila whereof passes upwardly through the cage I80. The passage lib communicates with the turbo-blower I! by means of a pipe llc. 1

Now, if the combustion engine is to be operated as 9. Diesel motor, the rotary three way valve It is rotated in the clockwise direction with the result that the gas supply conduit 8 will be cut oil and the gas supply port 6 is now brought directly into communication with the outside air through the conduit 8. In this position and with the slidevalve 2 in the position shown in the drawing, first compressed scavenging air is introduced again into cylinder C through the air supply conduit 1, the air supply-port 4 and the air inlet openings 3. Then, after the downward displacement ofthe slide-valve 2, the descending piston in cylinder draws in outside air through the conduit 9, the gas supply port 8 and the inlet openings 5, and finally, after the slide-valve 2 through a corresponding upward displacement has closed the inlet openings again, pre-compressed air is'introduced into cylinder 0 through the air-supply conduit l, the air-supply port 4 and the air-inlet openings 8. At I5 is shown a fuel nozzle for introducing fuel into the compressed air for Diesel operation.

arcane facing valve seat, said passage having an internal annular rib intermediate its ends providing inner and outer annular channels, a cylindrical valve cage in said passage and closing the upper end .thereof, said cage being seated on the reduced lower end of the passage and having said rib engaging its outer surface intermediate its ends, said cage having a set of ports affording communication between the outer channel and the interior of the cage, and having a second set-of ports affording communication between the inner channel and the interior of the cage, said head havingan upper and a lower lateral passage leading from respective channels for admitting gas and air to said channels, valve means in the upper passage controlling gas flow therethrough, a sleeve valve slidable in said cage to open and close said ports, a stem carrying said valve, 8. poppet valve fixed to the lower end of said stem to open and close the lower end of the cage, the second of said set of passages forming means for admission of Diesel fuel, said head having an exhaust port leading laterally from the third passage. and an exhaust valve fitted in said third passage.

ALFRED SC 

